Drought in the forest breaks plant–fungi interactions

European Journal of Forest Research - Drought in the forest is not only a prolonged state of water shortage, but also an occasion where interactions between plants and fungi are affected. Water...     

Assessment of 137Cs and 239,240Pu Distribution in Forest Soils of the Opole Anomaly

Distribution of ¹³⁷Cs and ^239,240Pu in the forest soils horizons of the Opole Anomaly was established. Gamma and alpha spectrometry was used for determination of these isotopes. It was found that the ¹³⁷Cs activity was approx. 1,000 times higher than that of ^239,240Pu. The highest activities of both radioisotopes were found close to the boundary region in soil profile where the organic horizon turns into the inorganic one. Cluster analysis did not clearly indicate the group’s existence in data in respect to ¹³⁷Cs and ^239,240Pu activities and organic matter content. Distributions of ¹³⁷Cs and ^239,240Pu in soil horizons were non-normal but similar to each other. These distributions were substantially different from that one for organic matter content. The data were separated into two groups, for organic and inorganic soil horizons, respectively. Data transformation using Box–Cox formula was performed following by standardization. Mutual relationships between variables were investigated using ordinary and robust regression methods. Good correlation between ¹³⁷Cs and ^239,240Pu was found. No significant relationship between organic matter content and radioisotopes activity was asserted.     

Does 2-hydroxyflutamide Inhibit Apoptosis in Porcine Granulosa Cells? - An In Vitro Study

In mammalian ovaries, the majority of follicles are lost before ovulation by atresia. This degenerative process is initiated or caused by granulosa cell apoptosis. To reveal the androgen-dependent mechanism of selective follicular atresia, the culture model system for agonism and antagonism of the androgen receptor has been established. We examined the influence of an androgen receptor antagonist, 2-hydroxyflutamide (2-Hf), on the incidence of apoptosis in cultured porcine granulosa cells. They were incubated (6 and 12-h) in the presence of testosterone (T, 10(-7)M), 2-Hf (1.7×10(-4) M) or both T and 2-Hf (T+2-Hf), and then analyzed by flow cytometry with fluorescein labelled annexin V. To better imitate in vivo conditions, the intact porcine follicles (6-8 mm in diameter) have been incubated in an organ culture system with the addition of the same factors. Sections obtained from follicles fixed after culture were stained with hematoxylin and eosin, and the presence of apoptosis-related DNA strand breaks was evaluated by the TUNEL method. Estradiol and progesterone concentrations in the culture media were measured by radioimmunoassays. The addition of T or 2-Hf to the culture media caused an increase in the number of apoptotic granulosa cells, while treatment with T+2-Hf decreased it in both in vitro and organotypic models. Follicles cultured with the addition of T or 2-Hf exhibited morphological changes indicating follicular atresia. Granulosal estradiol secretion was considerably stimulated by T+2-Hf. The highest increase in follicular estradiol secretion was observed after the anti-androgen addition. In both granulosal and follicular cultures, the production of progesterone declined in the presence of T or 2-Hf but increased after their simultaneous addition. In conclusion, androgen receptor antagonist 2-Hf attenuates induction of granulosa cell apoptosis in the presence of a high T level. The nature of this protective mechanism as yet is unknown and requires further research.     

Fruit Yield of Tomato Cultivated on Media with Bicarbonate and Nitrate/Ammonium as the Nitrogen Source

ABSTRACT

This article presents the effects of nitrate/ammonium (NO₃ ^?/NH₄ ⁺), applied at different proportions to the root media with or without 5 mmol bicarbonate (HCO₃ ^?), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically (pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four clusters obtained from plants grown on the medium with NH₄ ⁺ was about 25% lower than from the plants grown on the medium containing NO₃ ^? as the nitrogen (N) source. Supplying NO₃ ^?/NH₄ ⁺ at a ratio of 4:1 increased the fruit yield by about 20% in comparison with the value recorded for NO₃ ^??plants. The enrichment of the medium with HCO₃ ^? stimulated the bearing, while the result depended on the ratio of NO₃ ^?/NH₄ ⁺. A combined treatment of HCO₃ ^? with NO₃ ^? or NH₄ ⁺ in the medium increased yields by about 28% and 11%, respectively, in comparison to plants cultivated without HCO₃ ^?. The application of NO₃ ^?/NH₄ ⁺ at ratios of 4:1 and 1:1 with HCO₃ ^? increased the respective yields by about 16% and 10% in comparison with plants grown without HCO₃ ^?. Modifications in the composition of the media affected the accumulation of organic solutions in the fruit. The NH₄ ⁺ nutrition effected a 20% decrease in the accumulation of reducing sugars in the fruit in comparison to the fruit of plants grown in media with NO₃ ^?. In the cultivation of plants in media with various NO₃ ^?/NH₄ ⁺ proportions the intermediate values of the reduced sugar concentrations were recorded in comparison with the values obtained for NO₃ ^??plants and NH₄ ⁺?plants. The enrichment of media with HCO₃ ^? increased the concentration of sugars in fruit from about 28% (for NO₃ ^??plants) to about 10% (for NH₄ ⁺?plants).

Malate and citrate are the main constituents of carboxylates in tomato fruit. The form of nitrogen applied to the medium did not significantly affect the concentration of carboxylates in fruit. Significant differences in carboxylate concentrations appeared in fruit grown on media enriched with HCO₃ ^? ions. In comparison with the cultivation without HCO₃ ^?, increases in the accumulation of carboxylates varied from about 22% to 30% depending on the form of the applied nitrogen. The concentration of amino acids in the fruit of plants grown with NH₄ ⁺ exceeded that in NO₃ ^??plants by about 55%. In the plants grown on media of modified NO₃ ^?/NH₄ ⁺ proportions, the concentration of amino acids in fruits were positively correlated with the level of NH₄ ⁺ in the medium. The enrichment of media with HCO₃ ^? stimulated a further increase in amino acid concentration in fruit by about 9% in NO₃ ^? plants and about 21% in NH₄ ⁺ plants compared with the respective control (without HCO₃ ^?).     

Yield of dry mycelium of Trichoderma viride Pers. ex Fr. on some carbon and nitrogen sources

This work reports results of mycelial yield of Trichoderma viride from a number of carbon and nitrogen sources and different C:N ratios. The ratios were in two series: first by increasing the carbon content (d-glucose as standard), second – by decreasing the nitrogen content (1-as-paragine as standard). The best mycelium production was found on d-xylose and glucose as C sources and KNO³ and 1-asparagine as N sources. Increase in dosage of both sources caused increase in yield but different changes in pH, according to how nutrients were utilised.     

Stability of saponins in alcoholic solutions: ester formation as artifacts

Saponins containing a free carboxylic group in the molecule give the corresponding esters as artifacts when stored for a long time in alcoholic solutions. Two saponins from Medicago sativa L., chosen on the basis of their different positions of the carboxylic group in the molecule, were refluxed with methanol and ethanol under neutral conditions. 3,28-di-O-glu medicagenic acid possesses a carboxylic group on the triterpenic moiety, whereas soyasaponin I, a glycoside of soyasapogenol B, has a glucuronic acid unit as the first sugar linked to the triterpene structure. Artifacts were quantified by HPLC. The peaks identified as the corresponding esters were examined during boiling from 1 h to 5 days. Quantitative results indicated that the carboxylic group on the sugar moiety, as for soyasaponin I, is more reactive than that on the triterpenic structure, as for 3,28-di-O-glu medicagenic acid. Saponins having the free carboxylic groups create enough acidity in their alcoholic solutions to catalyze the formation of the corresponding esters.     

Triterpenoid glycosides from leaves of Medicago arborea L

Eighteen triterpene saponins (1-18) from Medicago arborea leaves have been isolated and their structures elucidated by spectroscopic, spectrometric (1D and 2D NMR, FAB-MS, ESI-MS/MS), and chemical methods. They have been identified as glycosides of medicagenic, zanhic, and 2beta-hydroxyoleanolic acids, soyasapogenol B, bayogenin, and 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid. Twelve of them, identified as 3-O-beta-D-glucopyranosyl-28-O-[alpha-L-arabinopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside] zanhic acid (3), 3-O-beta-D-glucopyranosyl-28-O-[beta-D-xylopyranosyl(1-->4)-[alpha-L-arabinopyranosyl-(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside] zanhic acid (4), 3-O-[alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->2)-beta-D-glucopyranosyl]-2beta-hydroxyoleanolic acid (5), 3-O-beta-D-glucuronopyranosyl-28-O-[alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside]medicagenic acid (6), 3-O-beta-D-glucuronopyranosyl-28-O-[beta-D-xylopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside]bayogenin (9), 3-O-beta-D-glucuronopyranosyl-28-O-[beta-D-xylopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside]-2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid (10), 3-O-beta-D-glucuronopyranosyl-28-O-[beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside]zanhic acid (12), 3-O-beta-D-glucuronopyranosyl-28-O-[beta-D-xylopyranosyl(1-->4)-[alpha-L-arabinopyranoside(1-->3)]-alpha-L-rhamnopyrano-syl(1-->2)-alpha-L-arabinopyranoside]zanhic acid (13), 3-O-beta-D-glucuronopyranosyl-28-O-[beta-D-xylopyrano-syl(1-->4)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside]zanhic acid (14), 3-O-[alpha-L-arabinopyranosyl-(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-28-O-[beta-D-xylopyranosyl(1-->4)-[beta-D-apiofurano-syl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranoside]zanhic acid (16), 3-O-[beta-D-glucopyrano-syl(1-->2)-beta-D-glucopyranosyl]-28-O-[beta-D-xylopyranosyl(1-->4)-[alpha-L-arabinopyranosyl(1-->3)]-alpha-L-rhamno-pyranosyl (1-->2)-alpha-L-arabinopyranoside]zanhic acid (17), and 3-O-beta-D-glucuronopyranosyl-28-O-[beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyrano-side]medicagenic acid (18), are reported as new natural compounds. The presence of the aldehydic group on the sapogenin moiety of saponin 10 is discussed in the framework of a possible elucidation of the biosynthesis of these metabolites.     

Effect of mebendazole on hydatid cysts in pigs

Mebendazole given per os was found to be effective against larval Echinococcus granulosus infection in pigs. Twenty-four pigs were experimentally inoculated with adult E. granulosus tapeworms. Mebendazole (40 mg/kg) or placebo was injected into six pigs 2 months after infection. Seven other pigs were given mebendazole (25 mg/kg) in their feed for 10 days twice (2 and 5 months after infection). Post-mortem examination performed 8 months after infection revealed that two of the pigs treated with mebendazole per os had a single hydatid cyst each; the other five pigs were free of infection. All eleven control untreated pigs were infected with between two and 21 cysts of E. granulosus.Mebendazole given intraperitoneally was not effective as mebendazole given per os in preventing the development of hydatid cysts in pigs.     

Effect of intraperitoneal inoculation of mebendazole on Taenia saginata cysticercosis in calves

Mebendazole was injected intraperitoneally at a dose of 40 mg/kg into six calves that had been inoculated 6 weeks earlier with eggs of T. saginata. The lethal effect of the drug on cysticerci was not significant in the mebendazole treated animals in comparison with those treated with a placebo. This was evaluated by counting the total number of cysticerci in each calf and the relative numbers of viable and degenerated cysts, an in vitro test for viability of cysticerci, and histological examination of the infected muscle tissue.